Emitter and method for emitting light

1. An emitter for emitting light, comprising a substrate having a substrate surface, at least one LED element arranged on the substrate surface for generating the light to be emitted, and an active cooling unit for cooling the at least one LED element with at least one cooling channel for a coolant, wherein the at least one cooling channel is arranged in a beam path of at least a part of the light to be emitted which can be generated by means of the at least one LED element, for redirecting the light to be emitted, wherein the redirection of the light to be emitted takes place without changing a frequency of the light to be emitted, wherein the at least one LED element and the at least one cooling channel are embedded in a transparent encapsulation, wherein a refractive index nE of the transparent encapsulation is greater than a refractive index nK of the cooling channel, and wherein a surface tangent of a region of a cooling channel boundary surface of the at least one cooling channel facing the at least one LED element runs at an angle d to the substrate surface, where the following applies: d≤90°−sin−1(nK/nE).

2. The emitter according to claim 1, wherein at least part of the light to be emitted can be redirected by the at least one cooling channel in the direction of a predefined main emission direction.

3. The emitter according to claim 1, wherein at least part of the light to be emitted can be redirected by the at least one cooling channel in a main emission direction defined to be perpendicular to the substrate surface.

4. The emitter according to claim 1, wherein a cooling channel boundary surface of the at least one cooling channel is formed, at least in regions, in such a way that at least one portion of the light to be emitted is reflected at the cooling channel boundary surface.

5. The emitter according to claim 1, wherein the at least one cooling channel is arranged adjacent to the at least one LED element, in a plane formed by the substrate surface.

6. The emitter according to claim 5, wherein the at least one LED element adjoins the at least one cooling channel on at least two sides in the plane defined by the substrate surface.

7. The emitter according to claim 5, wherein a region of a cooling channel boundary surface of the at least one cooling channel which faces the respectively adjacent LED element extends away from the adjacent LED element with increasing distance from the substrate surface.

8. The emitter according to claim 1, wherein the at least one cooling channel is formed as a cavity in the encapsulation.

9. The emitter according to claim 1, wherein the encapsulation comprises at least one of the group comprising a silicone elastomer and a resin.

10. The emitter according to claim 1, wherein the encapsulation comprises at least one of the group comprising a silicone elastomer and an epoxy resin.

11. The emitter according to claim 1, wherein a cross-section of the at least one cooling channel is polygonal in shape.

12. The emitter according to claim 1, wherein a cross-section of the at least one cooling channel is triangular.

13. The emitter according to claim 1, wherein the at least one cooling channel has an extension perpendicular to the substrate surface of between 1 mm and 20 mm.

14. The emitter according to claim 1, wherein the at least one cooling channel has an extension perpendicular to the substrate surface of between 1 mm and 15 mm.

15. The emitter according to claim 1, wherein the at least one cooling channel contains a coolant comprising ethylene glycol.

16. A method of emitting light by means of an emitter comprising the steps of: providing an emitter, comprising: a substrate with a substrate surface, at least one LED element arranged on the substrate surface for generating light to be emitted, and an active cooling unit for cooling the at least one LED element, with at least one cooling channel for a coolant, wherein the at least one cooling channel is arranged in a beam path of at least a portion of the light to be emitted which can be generated by means of the at least one LED element, generating the light to be emitted by means of the at least one LED element, cooling of the at least one LED element by means of the active cooling unit and redirecting at least a portion of the light to be emitted by means of the at least one cooling channel, wherein the redirection of the light to be emitted takes place without changing a frequency of the light to be emitted, wherein the at least one LED element and the at least one cooling channel are embedded in a transparent encapsulation, wherein a refractive index nE of the transparent encapsulation is greater than a refractive index nK of the cooling channel, and wherein a surface tangent of a region of a cooling channel boundary surface of the at least one cooling channel facing the at least one LED element runs at an angle d to the substrate surface, where the following applies: d≤90°−sin−1(nK/nE).

17. The method according to claim 16, wherein at least one portion of the light to be emitted is deflected by the at least one cooling channel in the direction of a predefined main emission direction.

18. The method according to claim 16, wherein at least one portion of the light to be emitted is deflected by the at least one cooling channel in the direction of a main emission direction defined to be perpendicular to the substrate surface.

19. The method according to claim 16, wherein the redirection of at least one portion of the light to be emitted takes place by reflection at a cooling channel boundary surface of the at least one cooling channel.

20. The method according to claim 16, wherein the redirection of at least one portion of the light to be emitted takes place by total reflection, at a cooling channel boundary surface of the at least one cooling channel.